Fig. 2: Dependence of the JQF reflection spectrum on probe power. | Nature Communications

Fig. 2: Dependence of the JQF reflection spectrum on probe power.

From: Breaking the trade-off between fast control and long lifetime of a superconducting qubit

Fig. 2

a, b Amplitude and phase of the reflection spectra of the JQF measured via the control line. The dots (blue, orange, red) are the experimental results with different probe powers, and the black lines are the theoretical fits for  −120 and  −146 dBm. The probe power of  −120 dBm corresponds to the single-photon power level for the JQF, defined as \(\hslash {\omega }_{{\rm{f}}}{({\gamma }_{{\rm{ex}}}^{{\rm{f}}}+{\gamma }_{{\rm{in}}}^{{\rm{f}}})}^{2}/(4{\gamma }_{{\rm{ex}}}^{{\rm{f}}})\), which would populate a linear resonator with a single photon on average30. Note that the qubit transition is not observed here since the resolution of the probe frequency is larger than the qubit linewidth.

Back to article page